If you're having USB 3.0 issues with a portable HDD, it might be worth trying a new cable.
I have a Western Digital My Passport SE 1TB, and it always refused to mount. I was only able to get it to work once maybe every 50 tries. I figured it was an issue with Apple's implementation of USB3 since this drive worked on my PC and others complained of the same issue. However the other day I borrowed my roommates harddrive (same model) and to my surprise it mounted right away. I then tried his cable on my drive, and that worked too. So I ordered a new cable from Amazon and everything is working great now. Mounts every time.
Doing some more research online, it seems a decent number of people got faulty cables from WD, so it might be worth even making a warranty claim
I have a Western Digital My Passport SE 1TB, and it always refused to mount. I was only able to get it to work once maybe every 50 tries. I figured it was an issue with Apple's implementation of USB3 since this drive worked on my PC and others complained of the same issue. However the other day I borrowed my roommates harddrive (same model) and to my surprise it mounted right away. I then tried his cable on my drive, and that worked too. So I ordered a new cable from Amazon and everything is working great now. Mounts every time.
Doing some more research online, it seems a decent number of people got faulty cables from WD, so it might be worth even making a warranty claim
